It’s all spelled out in the U.S. Anti-Doping Agency report that finally took Armstrong down, exposing him as a doper extraordinaire and the biggest fraud you’ll find on two wheels. Someone finally stood up to the bully and called his bluff, and now the dominos are falling fast.

So fast that before the day was done, Armstrong had been abandoned by another major sponsor. Anheuser-Busch said it wouldn’t re-sign Armstrong, though both the beer company and Nike said they would continue to support his foundation. Other smaller sponsors followed.

That it took this long is a testament to how elaborate Armstrong’s doping schemes were and how adamant his denials were framed. That it finally happened is thanks to the tenacity of Travis Tygart and others at the doping agency who wouldn’t quit even when federal prosecutors had given up their pursuit of Armstrong.

The seven Tour de France titles will be the next to go, because even the inept people who run international cycling must now realize it’s the only way to restore even a sliver of legitimacy to the drug-addled sport. Nobody still believes Armstrong won riding clean, as if anyone believes anything about cycling anymore.

For years, Nike served as an enabler for Armstrong, promoting him as one of the greatest athletes ever, alongside the likes of Kobe Bryant and Tiger Woods. They paid him millions to ride with the swoosh, and aired commercials showing him doing supernatural things on his bike.

All the while, they conveniently ignored one nagging question: How could someone who was clean win seven Tour de France races against competitors who were mostly all doping?

The answer, of course, was that Armstrong wasn’t clean. Neither were the teammates who helped him win those races, some of whom would later say they had to dope because Armstrong would kick them off the team if they didn’t.

But Nike didn’t just use Armstrong to sell products. The company helped create and sell an image of Armstrong that was easy for people to buy.

He was a cancer survivor who fought to overcome the disease, an athlete who won simply because he worked harder than the competition. Both heroic and compassionate, he inspired others and gave them hope through the ubiquitous yellow bracelets that were the symbol of his crusade.

And now that he has been exposed as a cheat, Nike claims it never had a clue.

“Due to the seemingly insurmountable evidence that Lance Armstrong participated in doping and misled Nike for more than a decade, it is with great sadness that we have terminated our contract with him,” the company said in a statement almost as fanciful as the commercials it once ran.

Nike moved quickly for a business that took months to remove Joe Paterno’s name from its child development center in Oregon. Dropping Armstrong was especially damning considering the company stood behind Bryant and Woods during their well-publicized troubles and re-signed Michael Vick the minute he got back on a football field.

Unlike them, Armstrong can’t redeem himself by competing again. He’s tarnished for good, and not only are his endorsements gone, but his lucrative speaking career, too.

Meanwhile, any hope that all the good he has done with his cancer-fighting organization would outweigh the bad pretty much disappeared with the announcement that Armstrong is stepping down as chairman of Livestrong, the charity he founded. He still will serve on the board of directors, but it’s hard to imagine Armstrong can be the face of Livestrong any longer.

His resignation amounted to his first public concession that the allegations against him are sticking. About the only thing he can do next is something that seems unimaginable for a man who, for years, has attacked anyone and anything with a vengeance whenever there was an insinuation that he might be riding dirty.

If he cares as much about his charity as he claims — and no one is suggesting he doesn’t — he must come clean. And that means more than just vague talk about a “controversy” over his career.

Call a press conference and admit all. Say you cheated and made your teammates cheat, too. Tell the world you wish you had it to do all over again.

Shed a few tears and ask for forgiveness. Talk about living the rest of your life doing whatever you can to make amends.

It won’t restore Armstrong’s reputation. That’s gone.

But it might be the only way some of the good he has done survives.

Tim Dahlberg is a national sports columnist for The Associated Press. Write to him at tdahlberg@ap.org or http://twitter.com/timdahlberg.